doesn't mail require buying postage stamps in the US? I'd be pretty mad at my bank if they'd charge 50c or whatever for every rent payment i make (or rather, let them make, because i surely don't want to have to remember that every month).

I just tell my bank to send x amount each month to a preconfigured bank account so my landlord doesn't complain. I timed it to be on the day after I get my wages so it's always there. It's scheduled to go on to infinity unless I change it.

Mikeski wrote:A "What If" update is never late. Nor is it early. It is posted precisely when it should be.

mathmannix wrote:Shoeboxes obviously differ in dimensions by brand, but the United States Postal Service standard shoe boxes are 7.5" x 5.125" x 14.375", which Google calculator tells me is 9.05449298 liters. Let's say 9 liters. I don't have an actual shoe box handy to measure, but this seems like a reasonably-sized shoebox to me.

Right, but read their description, which says that the box "is designed to meet the needs of footwear and clothing retailers and direct-to-customer businesses. This box allows shippers to simply slide in a boxed pair of shoes for easy shipping."

This box has to be larger than every reasonably sized shoebox so that you can put the entire box directly inside of it.

Mutex wrote:I mean, you might as well say "You need a PEN to write a cheque? Newsflash: not everyone has the money for one of those or the ability to read and write."

Yes, and a couple hundred years ago that would have been a proportionately valid argument.

Your girlfriend's financial decisions are on her. It's not America's fault she doesn't take advantage of the free automatic money transfer service her bank almost certainly offers.

Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.---If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome

It's not totally equivalent. But In the UK access to internet is considered virtually equivalent to access to water, and computer skills about on par with reading and writing skills. So that's why I was surprised at your suggestion the requirement for an internet enabled device should be considered a barrier. But I guess there's plenty of very remote / rural areas in the US.

I'm not saying the cheque has absolutely no use case any more, I get the impression it's very over-used in the US compared to here though.

moody7277 wrote:I'm only certain of how to calculate the number of digits of the first third of that monstrosity in the check. It's something like 10^4500 digits, plus whatever the Knuth and that third bit add.

How did you get 104500? I got 3x103000, so one of us (at least) has made an error.

Fortunately, it doesn't matter, because the second term completely dwarfs the first. 20^^^^20 is a completely unimaginable power tower of 20's. It's a number so large, that the number of digits of 20^^^^20 - in any reasonable notation - would simply be the number itself. Actually, it''s so large, that the height of the power tower would be indistinguishable from the number itself. Four-arrow numbers are g*d f***ing huge.

As for the last term, Su(1000), I have no idea what it means.Someone suggested Busy Beaver, but I've never seen the BB function written with 'u' as a subscript. At any rate, if it is the busy beaver function, than:

(1) nobody has a clue what BB(1000) is. Since the function is non-computable, there's little chance we'll ever know. And even if we did know, there's little chance one could write it down in any form of standard notation (at least not one that currently exists).

(2) We know from (extremely weak) lower bounds, that even BB(25) is far greater than 20^^^^20.

But somehow, I don't think Su(1000) is a Busy Beaver function. Not like Randall to use a number nobody would be able calculate.

In the same vein as the original question, filling the shoebox with MicroSD cards full of legally purchased ebooks would be surprisingly expensive, especially if they were academic books. Text takes up very little space, and academic books tend to have few pictures. The average ePub file, containing a few pictures, is around 3 MB, and an academic text costs at least $10, average probably around $20. This makes it about 20 times as expensive as the box filled with music.

It looks like Sbb to me, which may be the number of steps in the busy beaver of that number rather than the number of 1s that Sigmabb is.

It also occurs to me that I was wrong about the largest possibly physically meaningful finite integer. My new candidate is "Take the power set of the phase space of the observable universe and encode that set in the most efficient[1] possible way as a series of integers. Then create a new number where that series of integers are the magnitudes of it's prime factors."

Probably (Certainly, since it's computable) smaller than anything involving BBs, but may get close to some of Randall's smaller big numbers without them.

Just how widespread is the problem? Consider this: according to a 2007 survey of U.S. banks conducted by the American Bankers Association, eight in ten banks incurred check fraud losses in 2006. And the total amount of check fraud attempted for the year totaled a whopping $12.2 billion. Worse yet, the ABA goes on to report that check fraud is growing by 25 percent per year. Reports from the business sector are equally troublesome. According to an Association of Financial Professionals survey, nearly two thirds (72%) of all businesses faced attempted or actual payments fraud in 2006. What’s the total damage? Check fraud estimates from Nilson Reports peg the sum at nearly $20 billion a year.

Today the problem is four times as large as it was in 1993, and remember that was after the banks had enough and the UCC was changed. According to figures from the Nilson Report in 2003, check fraud exceeded $20 billion per year. This is a significant increase from the $5 billion figure reported in 1993 and 1996

Nah, clearly no problem!

So, enlightened Eurotrash, does every landlord, independent tradesman, and, frankly, every private citizen have some sort of EFT account and carry card-swipers with them?

Practically every business, actually

That's not the question that was asked. The question that was asked was about landlords, tradesmen, and private citizens. "Practically every" business in the US has card readers, too.

Nice job clipping out my "but that's a side topic" calling out your red herring. It's completely unnecessary because, as this entire conversation has been about, people use bank transfers.

If I want to send you $70 by instant bank transfer, what equipment do we both need? Because for a check all I need are the physical check, a pen, and a stamped envelope. If I'm standing next to you, I don't even need the stamped envelope.

Yeah, you only need a box full of checks that you have to pay for and can run out of and have to order more, 40+ cents for stamps and envelopes that you can also run out of, access to a post box, and the recipient has to take time out of their day (and pay for transportation costs) to go to their bank (unless they have automatic check depositing software or hardware that maybe 2% of Americans have), and then wait days for it to clear (and hope that it doesn't bounce) - easy as pie, such little requirements and inconvenience!

Iceland used to use checks. We gave it up when we entered the modern era because it was so patently obvious an inconvenient, expensive, slow, fraud prone, bookkeeping-error-prone way to pay compared to digital transfers.

without the need for any special hardware any more significant than a computer or smartphone

Ah, so you need a computer or smartphone to do this.

Newsflash: not everyone has the money or inclination for one of those.

Newsflash: 96% of Icelanders do, the highest rate in the world among independent countries:

... which renders it about 0,01% as useful. Wake me up when you hire some random tradesman to a job for you, then realize after he's done that you've lost your wallet (or in your case, your checkbook ), and so simply pull out a smartphone and pay him with a peer-to-peer money transfer app because you know 100% he can accept the money and is fully comfortable doing so because it's a part of his everyday life. Wake me up when all of your bills, everything from power to rent to government services, flow automatically into the peer-to-peer app into a to-pay inbox, complete with digital documents describing the bills. Wake me up when everyone else around you is so comfortable with it that instead of walking around to collect cash for a bottle of wine for a coworker's gift, they just send an email under the expectation that obviously everyone would just do a peer-to-peer money transfer because it's easier.

Until that day... enjoy your backwater.

I suspect your intimate firsthand knowledge of America is at least as out of date as the end of those three decades you lived here.

General rule of holes: when you're in one, stop digging. I last lived in the US in spring of 2012, and visited as recently as this spring.

(Perhaps I should also inform you how ridiculous and backwards your social security number system is versus a kennitala... Naaaaahhhh..... )

So $20B appears to include attempted check fraud. Then you probably shouldn't report that as actual losses.

I never claimed it wasn't a problem, I claimed it was a problem you greatly overstated.

unless they have automatic check depositing software or hardware that maybe 2% of Americans have), and then wait days for it to clear

Now I'm confused.

Are smartphones something most people have (making them a viable option for p2p money transfers), or something almost no one has?

Newsflash: 96% of Icelanders do, the highest rate in the world among independent countries

Congratulations, you live in a country uniquely suited for internet-based money transfers, and your argument only leaves out 1/25 of your own country's population.

(Perhaps I should also inform you how ridiculous and backwards your social security number system is versus a kennitala... Naaaaahhhh..... )

Why not just let me choose from a whole list of legitimate problems the US has that you'll nonetheless greatly exaggerate in another attempt to critice American society as a whole, instead of this one-at-a-time bullshit.

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mathmannix wrote: You can't "hack" a check, but who knows what can happen when the computers and satellites know your information?

Sadly, checks are rather easily hacked. Granted, for a significant fee, you can have your bank refuse a check (at least under some circumstances), but more than once a crook printed his own checks w/ someone else's account number in the mag-ink codes along the bottom. I recall one case where a fella printed "vanilla" deposit slips with his account number on them and stuffed them in a bank's lobby. Everyone who used one of these slips to deposit ended up crediting the crook's account.

That's pretty stupid, considering you have to write your own account number on there. How do you not notice someone already filled it in?

While that is pretty stupid, I have several explanations for how this scam would work: (1) If I am going through the drive-through, the bank teller fills out the deposit slip for me. (2) New checkbooks come with 5 or 10 deposit slips (with the account number correctly filled in already), so people might be used to that. (3) With direct deposit of my paycheck, tax return, etc., I rarely (if ever) have to use a deposit slip, so I might not notice if it doesn't look normal. I don't usually have a bunch of cash or checks that I want deposited; I'm much more likely to be withdrawing money if I visit the bank in person. If somebody writes me a check (like for my birthday or something) then I usually just cash it and spend the cash. The only times I remember depositing checks are the few times when there were a bunch of them, like my graduation and wedding, or when it was a personal check for a large amount (more than $200, say), which doesn't happen very often either.

I'm no expert, but it seems to me that using cheque fraud numbers from over 10 years ago is somewhat problematic, at best, and dishonest or misleading at worst. I say that because I can think of a significant number of changes in the economy of the world since 2003, not the least of which are the invention and spread of the Smartphone (yes, folks, smartphones weren't a thing in 2003), the increase in ACH, and the increase in online shopping.

As far as auto-paying bills, I find the concept rather convenient as someone who suffers from CRS (or, more likely, absent-minded-professorism), but I stopped participating in most auto-pay systems after a few overdrafts-gone-horribly-awry. Going through even a short period of living paycheck-to-paycheck (or even living without a paycheck) will certainly change one's habits in terms of how bills get paid. I hope to never again have to make the decision of which bills I can "put off" until I can afford to pay them (heat can't legally be turned off in the winter, for example), but I tend to still operate as if my next paycheck may be my last for the forseeable future.

There's also something that feels inherently disconnected when it comes to using auto-pay. By taking the time to write out a cheque, use cash, or even just use my bank's bill-pay system to pay a bill, it leaves me in touch with the idea of how much money I have and how much I'm spending. I firmly believe that if people in the U.S. were required to write a cheque to the government every month instead of having their employer automatically deduct their taxes, there would be a better appreciation of just how much money is being spent to run the government. Hiding transactions behind automatic payment plans, plastic cards, and electronic screens serves to devalue the appreciation for money and what it can or can't do for people.

I applaud the people of Iceland for leading the charge on electronic payments; someone's gotta do it. But it's rather futile to attempt to compare one country's economy to that of another country, especially with the diversity of population density, land area, overall population, founding philosophies, age of country, etc. And flinging around insults about other people's country or culture are counter-productive to reasonable discourse.

squall_line wrote:I'm no expert, but it seems to me that using cheque fraud numbers from over 10 years ago is somewhat problematic, at best, and dishonest or misleading at worst. I say that because I can think of a significant number of changes in the economy of the world since 2003, not the least of which are the invention and spread of the Smartphone (yes, folks, smartphones weren't a thing in 2003), the increase in ACH, and the increase in online shopping.

Yeah, that's a good point as well.

Icelanders weren't using their smartphones to do P2P bank transfers back when those statistics (on real and attempted check fraud) were gathered, either. If they've managed an almost complete turnaround in the subsequent 7-10 years, it's only to be expected that the US, with a thousand times more people, would take a bit longer.

Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.---If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome

Arancaytar wrote:I've never seen the notation on the right - what is [imath]S_**(1000)[/imath]?

I'm assuming that much like [imath]1000^1000^1000[/imath], it is a completely negligible number next to 20↑↑↑↑20.

I'm pretty sure its the other way around.

I don't think Randall would have bothered with a notation such as S_u(1000) (or whatever that subscript really is) unless it was some powerful recursive function. And while 20↑↑↑↑20 is unimaginably huge when compared to ordinary numbers (and I include 1000^1000^1000 in the category of "ordinary"), it will be easily dwarfed by nearly any such function if you plug "1000" into it.

Case in point: The Ackermann Function of 7 is already far larger than 20↑↑↑↑20. And Ackermann is one of the simplest and most tame of these functions, which was invented over 80 years ago.

Randall seems to be under the impression (see the tooltip on the diamond image) that Google still allows the "+" prefix. Unfortunately, those morons discontinued it, which is why I'm currently using DuckDuckGo in protest.

macronencer wrote:Randall seems to be under the impression (see the tooltip on the diamond image) that Google still allows the "+" prefix. Unfortunately, those morons discontinued it, which is why I'm currently using DuckDuckGo in protest.

And the fact that Google declared itself as "Big Brother" and decided they must know everything about everyone, didn't play any role in your decision?

DuckDuckGo gets my vote, for this reason and this reason alone. Too bad that it isn't that good a search engine yet. Not that it's a bad one, mind you. It just isn't sufficiently good to get me the info I want on a regular basis, which forces me to return to Google far more often than I would like.

macronencer wrote:Randall seems to be under the impression (see the tooltip on the diamond image) that Google still allows the "+" prefix. Unfortunately, those morons discontinued it, which is why I'm currently using DuckDuckGo in protest.

And the fact that Google declared itself as "Big Brother" and decided they must know everything about everyone, didn't play any role in your decision?

Well actually, yes it did. They've definitely been getting too full of themselves. The G+/YouTube fiasco also annoyed me, though I have to admit they eventually resolved that one to my satisfaction (i.e. I can now use YouTube under my original account rather than being forced to use a G+ one).

PsiSquared wrote:DuckDuckGo gets my vote, for this reason and this reason alone. Too bad that it isn't that good a search engine yet. Not that it's a bad one, mind you. It just isn't sufficiently good to get me the info I want on a regular basis, which forces me to return to Google far more often than I would like.

I know what you mean. It's pretty good most of the time, but it's not quite the same. Hopefully they'll keep refining and improving it.

There’s an old Ripley’s Believe it or Not that mentioned an iron bar worth $5 becomes worth $10.50 if you forge the iron into horseshoes, and worth $3,285 if you make it into needles. And if you turned the iron into watch springs, it would be worth $250,000.

That made me wonder: how much is a shoebox full of watch springs worth?

So there is actually a known density for a perfect crystal of freebased cocaine, and that is 1.25 g/mL (Yes, I know that the likelihood of getting a perfect crystal of cocaine big enough to fill a shoebox approaches zero, but whatever). This was calculated from an x-ray crystal structure of freebased cocaine.

Now, I cannot find a crystal structure publication of LSD, but ACDLabs (a chemical property calculator, among other things) predicts that a perfect crystal of LSD would have a density of 1.2 g/mL, with error of +/- 0.1 g/mL. The price per dose varies, but to the best of my knowledge it's roughly $10 a dose, with a dose being roughly 100mcg.

While I expected it to be more expensive, a shoebox of LSD will fully fund a decent sized research lab for a chemistry professor's career, which begs the question why more organic chemistry professors aren't going for that total synthesis...

For my money, I'd go with nuclear isomers. Precise values are hard to find but one rough estimate is 1 billion dollars per gram of hafnium 178m2. Although, many people think that if anyone wanted it in mass quantities this could probably be dropped by a few orders of magnitude, once you did the research and built a factory.

Something I would be curious to see, sort of derivative of this: if you had a Star Trek style replicator and unlimited power to run it on, how much of what should you make in what order to sell for the maximum profit?

That is, I'm assuming you make and sell whatever the most expensive thing in the world is until the market for that is saturated enough that it's no longer the most expensive thing in the world (because everyone willing to pay that much already has enough), then switch to whatever's the new most expensive thing, and so on.

Yea, no curator in their right mind is going to roll up The Card Players. If you want to put valuable art in a shoebox, historic jewelry, jewels, or small illuminated manuscripts(the Tres Riches Heures would just barely fit in and god alone knows what it would auction for; ditto possibly the Luttrell Psalter the Hours of Jean D' Evreux would likewise sell for an astronomical sum and it's about the size of a large matchbox) would all probably be the largest value-for-volume ratio.

Pfhorrest wrote:Something I would be curious to see, sort of derivative of this: if you had a Star Trek style replicator and unlimited power to run it on, how much of what should you make in what order to sell for the maximum profit?

AJMansfield wrote:Although, if you were to fill the shoebox with plutonium, it would not in fact cause a gigantic nuclear explosion, but rather only a small one, just enough to eject the plutonium ingots out and away from each other, ready for the next person to try it.

No, in fact, long before you could get that much plutonium together it would go critical, and the now liquid and gas plutonium would simply splash apart. No explosion. You can't use a gun to shoot it together either, because long before it gets close enough it goes critical, and again, hot molten metal splashes apart. (You don't want to be anywhere near this event)

sotanaht wrote:I think your mistake was where you assumed it would be in the form of ingots. In order to maximize cost/volume, any material fill would need to be solid. If you managed to assemble a SOLID shoebox-size block of plutonium, I doubt the explosion would be small.

The statement "So while you could fit 300 kilograms of it in a shoebox, you could only do so briefly." is not true, and can never be true. Even if you tried to use the implosion method to quickly shove it all together, that much PU would react long before it reached shoebox size. It's exactly why you can't use the gun style design for a bomb with Pu, it reacts far too quickly. Long before it's close enough to create an explosion, it simply turns molten or gas, along with everything else around it, splattering apart and stopping the criticality.

SFX wrote:The statement "So while you could fit 300 kilograms of it in a shoebox, you could only do so briefly." is not true, and can never be true. Even if you tried to use the implosion method to quickly shove it all together, that much PU would react long before it reached shoebox size. It's exactly why you can't use the gun style design for a bomb with Pu, it reacts far too quickly. Long before it's close enough to create an explosion, it simply turns molten or gas, along with everything else around it, splattering apart and stopping the criticality.

Surely there is a speed at which the subcritical chunks of plutonium would have enough momentum to fill a shoebox and then have a gun-type chain reaction.

SFX wrote:The statement "So while you could fit 300 kilograms of it in a shoebox, you could only do so briefly." is not true, and can never be true. Even if you tried to use the implosion method to quickly shove it all together, that much PU would react long before it reached shoebox size. It's exactly why you can't use the gun style design for a bomb with Pu, it reacts far too quickly. Long before it's close enough to create an explosion, it simply turns molten or gas, along with everything else around it, splattering apart and stopping the criticality.

You've linked to some stuff about explosions and critical solid mass, but I don't see anywhere that says you couldn't bring a bunch of subcritical bits of plutonium together uniformly into a shoebox-sized space very briefly.

Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.---If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome

The Trinity gadget and any other spherical implosion plutonium warhead uses this same basic approach, no? Not a gun-type assembly, exactly, but close enough.

Let's see. Approximating "a shoebox" by a simple sphere of plutonium massing 300 kg, the sphere would be just 31 cm across. This is about twice the diameter of the minimum bare-sphere critical mass of plutonium-240. However, if you formed fifteen rods of 20 kg each, 15.5 cm in length, they would each have half a minimum bare-sphere critical mass but be definitely subcritical. Fire all these together at the same point fast enough and you'd surely get your sphere.

I could be wrong here, but I assume that the reason atomic scientists/weapon designers make plutonium into spheres in the first place because it is the most concentrated shape, and therefore will go critical with the least amount of mass. So if you take a mass that, in sphere form, will be right on the cusp of going critical, and put it into any other shape (like a shoebox!), then it won't go critical, right?

mathmannix wrote:I could be wrong here, but I assume that the reason atomic scientists/weapon designers make plutonium into spheres in the first place because it is the most concentrated shape, and therefore will go critical with the least amount of mass. So if you take a mass that, in sphere form, will be right on the cusp of going critical, and put it into any other shape (like a shoebox!), then it won't go critical, right?

While the physics of how to make a plutonium bomb are "generally understood", the details are still secret. And I'm not about to reveal them here. But it is general knowledge that 10 kilos of plutonium is a critical mass. Anything more and the shape starts to not even matter, as Pu needs no moderator or reflectors once you get enough of it close together. 300 kilos would be dangerous even if it was just in the same room. Nobody even knows realistically at what point 300 kilos would start going critical, but a nuclear physicist could tell you.

But we do know this. If you used a 10 kilo sphere, took out a chunk, (like Uranium bombs are made) and tried to make a gun type bomb, long before the missing piece is slammed into the sphere, no matter how fast you shoot it, it will go critical long before they reach each other, turning everything into molten metal and gas, and it all flies apart with no bomb type explosion. This is the exact problem they originally faced, which is why they came up with a sub critical sphere, and explosions to drive it together to make it explode.

This is all in the history of the atomic age. Ask any nuclear scientist and they will tell you the same thing, since I got all this info from the scientist who built the bombs.

It's impossible to bring together 300 kilos of plutonium, even with explosives and engineering. That much Pu will start reacting long before the pieces get close enough. There is no way to do it. This is actually a good thing, since it would make an explosion about 10,000 or 100,000 times bigger than Hiroshima, with an unbelievable amount of fallout. Remember that one micro-gram of Pu-239 is enough to cause cancer if you breath it in. Putting 299,000,000,000 micro-grams of vaporized Pu-239 into the atmosphere would be a very bad thing. The 1,000,000,000 micro-grams of other radioactive material would also be very very bad.

mathmannix wrote:I could be wrong here, but I assume that the reason atomic scientists/weapon designers make plutonium into spheres in the first place because it is the most concentrated shape, and therefore will go critical with the least amount of mass. So if you take a mass that, in sphere form, will be right on the cusp of going critical, and put it into any other shape (like a shoebox!), then it won't go critical, right?

Right, but size is an issue. In sphere form, about 10 kg of plutonium is supercritical. That is less than you think: roughly the size of a softball. How many softballs can you fit in a shoebox?

The reason a sphere is the "best" shape is because it has the lowest surface area of any solid in proportion to its volume. Surface area hurts criticality; the more surface area you have, the more neutrons will be able to escape. But if you start packing softballs of plutonium into a shoebox, the surface area won't be an issue, because the spheres will be close enough to capture the neutrons from other spheres and you've got a hypercritical arrangement.

SFX wrote:While the physics of how to make a plutonium bomb are "generally understood", the details are still secret. And I'm not about to reveal them here.

The details needed to replicate the Trinity gadget are no longer classified and pretty much elementary. Of course, modern plutonium warheads use a more egg-shaped initial shell in order to decrease the complexity of the required chemical initiators and decrease the risk of a fizzle, and THAT shape is highly classified/secret, but a basic spherical implosion plutonium bomb isn't that hard to design. It's just getting the plutonium that's the hard part.

10 kilos of plutonium is a critical mass. Anything more and the shape starts to not even matter, as Pu needs no moderator or reflectors once you get enough of it close together.

That's not entirely right; in a narrow rod, you can have a LOT more than 10 kg of plutonium and still be safely subcritical. Even more if you use a thin "plank" shape.

Nobody even knows realistically at what point 300 kilos would start going critical, but a nuclear physicist could tell you.

It's a problem of density and surface area. The neutrons pouring out of a subcritical sphere will be subject to the inverse-square law, so it shouldn't take much space to arrange any amount of plutonium "safely".

But we do know this. If you used a 10 kilo sphere, took out a chunk, (like Uranium bombs are made) and tried to make a gun type bomb, long before the missing piece is slammed into the sphere, no matter how fast you shoot it, it will go critical long before they reach each other, turning everything into molten metal and gas, and it all flies apart with no bomb type explosion. This is the exact problem they originally faced, which is why they came up with a sub critical sphere, and explosions to drive it together to make it explode.

It's impossible to bring together 300 kilos of plutonium, even with explosives and engineering. That much Pu will start reacting long before the pieces get close enough.

I don't think anyone is talking about doing a pure gun-type assembly. Because you can make the rods of plutonium you're firing toward the center of your "shoebox" arbitrarily many and arbitrarily thin, and give them arbitrarily high momentum...it should be doable.

sevenperforce wrote:I don't think anyone is talking about doing a pure gun-type assembly. Because you can make the rods of plutonium you're firing toward the center of your "shoebox" arbitrarily many and arbitrarily thin, and give them arbitrarily high momentum...it should be doable.

If you're allowing arbitrarily high momentum, you could make a kinetic-energy bomb and not bother with the Plutonium... In fact you probably do better with something less dense since it'll have more kinetic energy per unit momentum.

Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.---If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome